1. Field of the Invention
The present invention relates generally to mechanisms for activating electrical switches. More particularly, the invention concerns an improved switch actuating mechanism for use with a keyboard assembly having a light source and embodying snap dome or similar type electrical switches.
2. Discussion of the Invention
A number of different kinds of switch actuating mechanisms for use in various keyboard applications have been suggested. These include elastomeric key pad actuators in a key matrix format and multiple, single function, discrete component switch activating assemblies. These latter assemblies are relatively complex and comprise a number of separate and discrete single function components such as light guides, light plates, plungers, return springs, contact pins, and contact actuating elements.
The prior art elastomeric key pad actuators typically comprise a "waffle-like" sheet which is provided with a number of actuator key elements arrayed in rows and columns. While these types of actuators are of simple design and include a minimum number of discrete components, they typically lack the ability to pipe sufficient light from adjacent light sources to effectively illuminate the actuating keys.
Other prior art switch actuating mechanisms include capactive, touch-type activators, optical interrupted beam type actuators and piezo-electric-type activators. As a general rule, these latter types of devices have limited applicability and are appropriate for only certain specialized applications.
As will better be appreciated from the discussion which follows, the switch actuating mechanism of the present invention exhibits numerous advantages over the prior art. For example, the device of the present invention is extremely simple in design, is highly reliable, is very inexpensive to manufacture and includes highly novel integrated light management features not found in any of the prior art switch actuating devices.